{ 232 ) 
The three-phase region for G -f- L -f- Sb , which is -formed by the 
successive three-phase-pressure lines g l s, runs at first with rise of 
temperature towards higher pressure, but finally descends again and 
terminates in tfye triple point of B. 
As fig. 2. shows particularly clearly, the peculiarity of the system 
ether-anthraquinone consists in this, that the plaitpoint-curve meets 
the three-phase region in the points p and q. 
Fig. 2, namely, gives the photograph of the spacial figure seen in 
the direction of the ,r-axis from A towards B. 
The line hr is the vapour-pressure line of solid B ; r is the triple 
point and rb the vapour-pressure line of liquid B terminating in the 
critical point b. 
The lines gp and qr are the projections of the broken three-phase 
region on the P,T-plane, and between a and p, and q and It 
found the two branches of the plaitpoint curve, which 
between p and q. 
If for the sake of simplicity we confine ourselves for the present 
only to the point p, it is noteworthy that in this point three remark¬ 
able points coincide, viz. the plaitpoint with the vapour pointy,and 
the liquid point l of the three-phase equilibrium G L -jr Sb^ 
So in this point p a saturated solution shows the critical pheno¬ 
menon, and when the mixture contains more B than corresponds 
-with the point, p, the said critical phenomenon will occur in t e 
presence of solid B at the temperature of this point. 
Exactly the same thing now applies to the second cntica en 
point q. • t 
Above the temperature of the point p solid B can on y c 
with a fluid phase, and the peculiarly curved surface npeaqw 
cates the fluid phases, which can be in equilibrii 
different temperatures and pressures. - t 
The upper part pedq passes continuously into the me\uapv> 
surfaces Ifep and qdcr (fig. 2), whereas the lower part join ^ 
nuously the vapour surfaces hgpn and mgr. It is now s 
apparent than before that p and q entirely agiee wi i ^ 
with only this difference that what is observed foi p w ’ . j 
temperature, takes place for q with fall of temperature. an( j 
shows that the continuous liquid-vapour surface teimma goiubilib' 
begins again at q. It is further worthy of note t a awards 
curve of B under the vapour pressure in normal cases ru 
higher concentrations of B at higher temperatuie. w nhthecoex- 
As, however, a saturated solution becomes identic ont j nu ously 
isting vapour at p, the solubility line Ip, fig- I> mus 
vith solid B at 
